Apparatus for producing and storing oxygen



Feb. 8, 1938. I ME SER 2,107,797

APPARATUS EOi-"i PRODUCING AND STORING OXYGEN Filed Oct. 17, 1936INVENTOR Aab lf'lyesser ATTORNEYS r Patented 8, 1938 UNITED STATESArrmrus roa raonuomo. ANDs'roR ING oxronn Adolf Mam,Frankfort-on-the-Main, Gem

Application October'- 17 1936, Serial No.'106,165 Germany September 4,1936 V 2 Claims. 7 (c1. 62 -122).

g In certain types of air separating plants for the production of oxygenand nitrogen, the liquid oxygen produced and collected in therectification column is forced out by a low pressure, for

instance about 0.5 atm into the oxygen evaporating coil on the lowpressure side oi the 'ap paratus where the liquid oxygen is evaporated.

The warmer or outlet end ofqthe oxygen evaporating coil is'generallyconnected to a gas hold- '10 er of the floating bell type where theoxygen accumulates and from which it is withdrawn-and compressed forstorage at a high pressure.

In many cases, especially where the oxygen isproduced at the, plantwhere it is to be con-,

sumed, a pressure of only about 10 atm. is required, so that anycompressing of the oxygen to I any higher degree, entails un'ne'cessaryexpenses. An oxygen producing plant suitable for such oxygen users hasbeen so well developed that even 0 an intermittent operation. of theplant is eco-' nomical and the accumulation of very large quantities of.oxygen in order to insure a cone .stantv supply'is not necessary.

i One object of the-present invention is to pro-- vide 'a process andapparatus for separating oxygen from airand storing said oxygen at asuitable pressure "for use without further compressing or the provisionforvery high pressure storwage. a

4 In carrying out thepresent invention, I proare advantageously directlyconnected with the bottom of the rectification column to receive the 7liquid oxygen from said column; After the re 5 ceiver'has been filled'toa predetermined level, the liquid-oxygen supply thereto is shut oif andthe stored oxygen isforcedthrough the oxygen evaporating coils formingpart of the heat inter changer for precooling the incoming air. The verylow temperature which exists in the filled I receiver normally inhibitsrapid evaporation of .the liquid oxygen, and in carrying out the presentinvention, pressure is utilized for forcing out the liquid oxygen fromsaid receiver. For instance, the second stage-of the aircompressor maybe utilized as such pressure means.

Preferably more than one receiver is provided,

andthe receivers are filled and emptied alternately so that while onereceiver is being filled, with liquid oxygen, the liquid oxygen whichhas [already been stored in the other receiver is forced by air pressurethroughv the oxygen evapcrating coils. as already pointed out. I

- 'At the outlet or warmer end of the oxygen 'vide one or more liquidoxygen receivers which evaporating coils, there is provided a storagegas liquid oxygen and effects the storing of the gase- 5 ous oxygen inthe holder at the desired pressure.

j In the accompanying drawing there is shown for. the purpose ofillustration, an apparatus which embodies the present infintion andwhich may be'used to carry out myimproved process.

In this drawing there is shown a column in having a heat interchanger ii; at the upper end for precooling the incoming air, and a rectifyingsection l2 at the lower end for separating the air into oxygen andnitrogen. The air is introduced under pressure through a coil 13 of theinterchanger l in countercurrent heat interchange relationship withthecoil ll through which the evaporation of the separated liquid oxygentakes place. This precooled air, after leaving the'heat interchanger ll,passes through a coil ii at the bottom of the rectifying sectionwherethe separated liquid oxygen collects,-and then through an expansionvalve It to a nozzle disposed over a series of trays i8.

As the resulting liquid air trinkles downwardly over the trays II, thenitrogen gas passes up- 'wardly'around the'heat. interchanger II and outthrough an outlet 20 while the oxygen collects in liquid form at thebottom 01 the column.

As a feature of the present invention, the liquid oxygen collected atthe bottom of the column III is gradually withdrawn 'and'temporarilystored in a receiver before passing through the heat interchanger coilll. As shown, a pipe 24 is con- 35 nected to the bottom of the column l0and has a pair of branch outlets 25 and 26 extending into I the tops'oftwo receivers 22 and 23, these branches being controlled byvalves 21 and28.

Extending substantially from the bottoms of the receivers 22 and 23 areoutlet pipes 30 and 3i forming branches of a pipe 32 connected to theinlet end of the oxygen evaporating coil i4. These outlet pipes areprovided-with valves 33 and SI. 45

Means are provided for forcingthe liquid from either of the receivers 22and 23 through the evaporating coil [4 of the heat interchanger ii. Forthis purpose there is provided a pipe 36.leading from a suitable sourceof pressure such as the second stage of the air compressor, and having apair of branch connections 31 and 38 which lead respectively into theupper ends of the receivers 22 and 23, and controlled by valves 40 andll.

The outlet end of'the oxygen evaporating coil l4 leads to a storageholder 42, the connection between said coil and said holder beingcontrolled by an adjustable regulating valve 43. This hold- 5 er 2 isprovided witha valved outlet 44 leadingto a' suitable point where theoxygen may be used in the workshop.v

As the oz-wgen is separated and collected in liquid form in the bottomof the column I, it is I delivered to and from the receivers 22 and 23alternately. As shown in the drawing, the valves 21, 34 and are openedand the valves 28, 33

and 40 are closed, so that the liquid oxygen is "being delivered throughthe valve 21 into the upper end of the receiver 22 while the liquidoxygen which has already been stored in the receiver 23 is forced by thepressure in the pipe 36 through the valve 34 and into the evaporatingcoll M. The evaporated oxygen leaving the 0011 ll passes. into thestorage holder 42 at a pressure depending on the adjustment of the valve43. When theliquidreaches the desired level in thereceiver as shown bythe gauge glass 45 or by other suitable means, the valves are reversed.By reversing the valves at the proper intervals, liquidoxygen may becontinuously produced and continuously withdrawn from the col- I umn atlow pressure, and liquid oxygen continuously evaporated and stored at areadily usable high pressure without the use of any additional pumpingor compressing mechanism.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:- 1 4 1. An air separating apparatusincluding a rectification column, aheat interchanger,- a liqthrough theheat interchanger.

2 An air, separating apparatus including a rectification column, a heatinterchanger, a pair 01' liquid'oxygen receivers, valved means betweenthe bottom of said rectification column and said receivers fordelivering liquid oxygen from said column selectively to either one ofsaid receivers,

valved means 'for delivering liquid oxygen from I either one ofsaidreceivers through said heat interchanger; and air pressure means forforcing the liquid oxygen from either one of said receiv- ADOLF' nmssna.

ers through said heatinterchanger.

